Drill



W. C. REA

Jan. 16, 1 934.

DRI LL Filed April 8. 1930 |N VENTOR (17?60..

ATTORNEY i 3d direction of the arrows.

Patented Jan. 16, 1934 UNITED STATES DRILL Walter C. Rea, New York, N. Y., assignmto Detachable Bit Corporation o! America, New York, N. Y., a corporation of Delaware Application April 8, 1930. Serial No.. 442,497

10 laims..

This invention relates to drills of the type com.-

prising afdrill rod and a bit detachably carried therewith, and more particularly to means for coupling such rod and bit.

I It has already been proposed to use a threaded coupling member to secure a bit to a drill rod in constructions of this character. When such a drill is percussively driven, as is usual, it is desirable that the impacts be transmitted. directly 10 from rod to bit or bit to rod, to relieve the coupling and the threads of such forces. At the same time,

the tendency of the coupling, dueto rotation oi the drill, to become wedged or jammed on either l the rod or the bit is to be avoided.

l@ The principal object of this invention is, therefore, to provide an improved construction whereby these desired advantages are secured and which is simple and inexpensive to manufacture, rugged and durable in service, and capable of being readd ily disassembled into its parts even after the drilling operation. A feature of the present invention resides in the location oi the means to prevent wedging entirely within the bit and rod.

Other objects and advantages ofthis invention ab will be apparent from the following detailed description of a preferred embodiment thereof, rei- `erence being had to the accompanying drawing wherein: s

Fig. 1 is a longitudinal, central section through tu the lower end of a drill rod, Fig. 2 is a side view of a coupling member and Fig. 3 is a side view of a bit. Fig. ll is a longitudinal, central section through the parts when assembled. Fig. 5 is a section on the lines 5--5 of Fig. 4 looking in the Fig. 6 is an end view of the construction, looking upwards with reference to Fig. 4.

There is shown at 1, a portion of a drin ma which is hollow as at 2 and formed with internal threads 3l A coupling member or stud 4 is formed with threads 5 and 6 at either end thereof and a flange 7 of annular shape intermediate the end of the stud. A bit 8 is provided with in ternal threads 9 for cooperation with the threads 6. The drill rod and bit are formed with enlarged openings l0 and 11, respectively, adapted to receive the flange 7, which is shown in abutment with shoulder 13.

It will be seen that the threads'3 extend for greater distances than the threads 5 so that when the portions are assembled the stud or coupling member does not abut against the upper end of the rod within the opening but rather the flange 7, when the stud is at its uppermost position abuts against the shoulder 12. The threads (Cl. Z55-64) on the stud all run in the same direction so that when thedrill is rotated in a given direction, in this case, counter-clockwise, when looking down, the tendency is for the stud to be turned into the drill rod and the bit on to the stud. The threads 6u are shown as the so-called undulatory type but although this form is preferred, it is not essential.

The flange 'l is of such dimensions that the height of its face 7a is less than the combined heights of side faces 10a, and lla of the enlarged 65 openings 10 and ll, but greater than either of the last named faces. When the parts are so proportioned a certain amount of travel is permitted the coupling member without danger of its flange becoming wedged against rod or bit. In 7G this construction, the face 14 of the rod abuts directly against the face 15 oi the bit. A slight clearance 16 is shown between the face 7a of the ange 'l and the surrounding portions of the rod and bit but this is not essential', as the parts may 'la lt snugly. A passage 17 is provided in the drill rod for the passage of liquid therethrough as is customaryr in the art.

Another feature of my improved construction lies in the provision of a cutting edge 18 on the so lower `end of the coupling member. I have found that this edge acts Vnot only as auxiliary to the cutting edges on the bit as the latter wear, but

l also prevents stalling of the bit against uncut portions of the material being drilled. as

Although I have described the specific embodiment of my invention in considerable detail, I do not wish to be limited save by the scope of the appended claims.

What I claim is: 9o l. In a device of the character described, the combination of a drill rod and bit each interiorly threaded in the same direction, a coupling member threaded'for cooperation therewith, shoulders formed within the rod and bit, and a flange on the coupling member for abutment with either of said shoulders when the parts are assembled, said ange being entirely enclosed within rod and bit, and being of less height than the combined heights of the side faces of said shoulders, 10o but greater than either of the latter, the rod being threaded to a greater extent than the threads on the coupling whereby the bit and rod are in abutment and the coupling may ride in either direction.

2. The combination of a drill rod and bit having a central opening extending therethrough, each threaded, a coupling member threaded for cooperation therewith, shoulderd means entirely= within the rod and bit when assembled adapted to permit the coupling member to ride a predetermined distance in either direction, and an auxil1 iary cutting edge on the lower end of said member.

3. In a rotary impact drill, the combination ofi two tubular sections, in end to end abutting relation, the bore of one of said sections being en larged at the end adjacent the other section to form a recess with parts oi the sections forming shoulder stops, a coupling having opposite ends in threaded engagement with the sections and having a flange disposed in said recess between said shoulders, spaced from one of the shoulders, and coacting with the shoulders to limit the movement of the coupling relative to the sections.

e. In a rotary impact drill, the combination of two separable sections, one constituting a drill rod and the other constituting a bit, in end to end abutting relation, a coupling connecting the two sections and in threaded engagement with one of the sections, said coupling having a slight freedom of rotary and axial movement relative to the section with which it is threaded, stop means for permitting and limiting such slight freedom of movement of the coupling and one end of the coupling being exposed through the bit and said exposed end provided with abutting edge.

5. In a rotary impact drill, the combination oi. two detachable sections, disposed in end to end abutting relation, each of said sections being internally threaded with the threads in one sec=I tion terminating in spaced relation to .the adjacent end of the section to leave a smooth, un'- threaded portion at the end oi' the section, a male coupling member enclosed within the sections, having opposite ends engaging the threads on said sections and provided'with a ange extending into said smooth unthreaded portion and said coupling adapted to be rotated into position to locate the ange in spaced relation to one of the sections thereby to permit a limited axial move= ment of the coupling relative to the abutting sections. v

6. In a rotary impact drill, the combination of a bit provided at one end with cutters fog a main cutting area, said -bit also provided with a bore extending axially therethrough and provided with threads, a one piece rod constituting a coin-a bined male coupling and supplemental drill pro-l vided with threads, said threaded end intruded into the bore of the bit engaging the threads in the bore thereof and said bit adapted to be threaded onto and off the intruded end of the coupling, said rod provided adjacent its mid= length with an outstanding flange fo a shoulder in abutting engagement with the bit, the portion of the rod projecting exterlally ci the bit provided with drill rod engaging means and said rod provided at the end intruded into the bit with cutting edges extending substantially in the plane of the cutting edges of the bit and substantially centered within the main cutting acca er@ two tubular sections in end to end abutting rela-f tion and provided with stop faces, the bores oi. said sections being threaded, a male coupling having opposite ends in threaded engagement with the sections and having a flange adjacent its midlength and positioned between the threaded ends, said flange having opposite sides facing said stop Iraces and one oiJ said sides spaced from. its opposing stop racea t. In a rotary impact drill, the combination of a tubular drill rod and bit in end to end abutting relation, said drill rod and bit provided with opn posing stop iaces axially spaced apart to form an annular recess, the end oi the drill rod which engages the bit provided with a threaded socket, a male coupling member having opposite ends in. threaded engagement with the drill rod and bit and provided with a ange contained in said recess and with one side or the flange in spaced relation to the stop face on the drill rod to provide a clearance therebetween, the threaded portion of said socket having a length greater than the length oi the portion of the male member intruded therein measured from said side of the ange to the extreme end of the intruded portion whereby the male member is free to turn until the nange engages the stop face on the drill rod and thus taire up the clearance before the end of the male member engages the end of the socket.,

9. In a rotary impact drill, the combination ci a tubular drill rod and bit in end to end abutting relation to form a joint extending at right angles to the axis oi rotation or the drill, the portion of the drill rod and bit on opposite sides of the joint being threaded with a screw thread of undulatory and continuously curved contour, the portion of the drill rod and bit forming the joint having less cross sectional area o material than the portions provided with the threads, a member for coupling together the drill rod and bit and provided at opposite endsv with a similar form o screw thread for engaging the threads on the drill rod and bit, the end of the member intruded into the bit provided with a cutting edge, the mid portion of the coupling member disposed at the joint and being or maximum cross sectional strength ci materiali and having greater cross sectional area of material than the threaded end portions.

lo. In a percussively driven rotary drill, the combination of a drill rod and bit in end to end abutting relation with the abutting ends provided with aligned threaded sockets, the abutting portion of the drill rod and bit each having less cross sectional area or material than the portions provided with the threaded sockets, and a male coupling member having opposite ends in threaded engagement with the sockets provided at one end with a cutting edge and provided intermediate its threaded ends with a portion oi maximum cross sectional area or material extending across the joint formed by the abutting ends of the drill red and WALT@ C. REA. 

